Motor-driven transport trolley with differentiated drive

ABSTRACT

This is a new motor-driven transport trolley comprising a frame with a rotating plate on top, having two sets of wheels, right and left, and two or more hydraulic motors which move the two sets of wheels separately to obtain differentiated drive. The motors are hydraulic and are fed by a pressure pump; the motion is differently distributed to the various hydraulic motors by means of valves connected to a control unit which controls the operation of the hydraulic motors, the pressure pump and the valves. This control unit is controlled by a push-button panel connected to it by means of an electric cable, infrared rays or radio waves, etc.

DESCRIPTION

[0001] This patent concerns the sector of porterage equipment andparticularly it concerns trolleys for shifting bulky and heavy objects.This patent specifically refers to a new motor-driven transport trolleywith differentiated drive on both sides. Transport trolleys are alreadyknown for voluminous and/or heavy objects. These trolleys comprise twoor more groups of broad wheels with small diameter. One of thesetrolleys is equipped with a rotating horizontal upper platform, on whichthe object to be transported rests, and a bar for towing and guiding thetrolley, while trolleys without a rotating platform are placed at therear. The trolleys composed as described above are towed by hand by anumber of persons.

[0002] Some trolleys are equipped with an electric motor which transmitsmotion to all the wheels of the trolley, in such a way as to make itless tiring to tow the object that is to be transported. Thoughconvenient, these motor-driven trolleys still present certain drawbacks,including the need for powerful motors to start towing the transportedobject (pickup) and the difficulty of going round bends since, as themotor acts simultaneously on all the wheels, it is not easy to turn thetrolley.

[0003] To overcome all the above problems, a new type of transporttrolley has been designed and implemented, equipped with hydraulicmotors which act independently on two or more wheels or groups of wheelsplaced on the two sides.

[0004] As regards its main parts, the new transport trolley comprises aframe or bearing structure, two wheels or sets of wheels, one or morepairs of hydraulic motors, a rotating horizontal upper platform and acontrol unit for the various motors.

[0005] The frame or bearing structure connects and joins the variousother parts. In particular it has a generally flat shape and therotating horizontal platform is placed on top.

[0006] This platform can turn with vertical axis in such a way as toallow the changing of the direction of the trolley with respect to theobject transported.

[0007] On each of the two sides of the frame or structure is placed aset of wheels with small diameter and broad width.

[0008] Each of the two wheels or sets of wheels receives motion,independently of the other, from one or more hydraulic motors.

[0009] In other words, two or more hydraulic motors serve and move thewheels of a right-hand set and of a left-hand set.

[0010] The connection between the hydraulic motor or motors and thecorresponding set of wheels may be achieved by means of cogged belts,chains with links or gears so that all the wheels in a set receiveexactly the same motion at the same time.

[0011] The control unit oversees and controls the operation of thevarious motors and is equipped with a push-button panel or a controlstick for controlling the movement of the trolley in the variousdirections. This push-button panel or control stick may be connected tothe control unit by means of an electric cable, infrared rays or radiowaves.

[0012] It is possible to allow for the various hydraulic motors toreceive the fluid from a single pressure pump connected to all themotors by means of two or more valves; the pressure differentiation, andtherefore the motion differentiation, is consequently determined by theclosing or the partial or total opening of the valves. The fluidpressure pump may be included in the trolley; preferably it may beseparate, for example transported on an auxiliary trolley moved by theoperator.

[0013] This solution offered by the new transport trolley allows eachset of wheels, right and left, to be moved independently of the other,that is, by moving the two sets of wheels in a differentiated manner, itis possible to obtain forward and reverse motion and turning of the newtransport trolley on the floor without any effort by the operator.

[0014] The power may be supplied to the control unit by the mains or bybatteries.

[0015] The following is just an example among many of a practicalembodiment of the invention in question, illustrated in the encloseddrawings, wherein:

[0016]FIG. 1 shows a plan view of the new transport trolley, while

[0017]FIG. 2 shows an axonometric view of the same transport trolley.

[0018] It is possible to observe the frame or bearing structure (1), thetwo sets of wheels (2.1, 2.2), the hydraulic motors (3.11, 3.12, 3.21,3.22) which set the wheels (2.1, 2.2) in motion. In these figures adashed line indicates the rotating horizontal upper platform (5) onwhich the object to be transported is placed.

[0019] In these example each set of wheels (2.1, 2.2) is composed offour wheels placed two by two (2.11, 2.12, 2.21, 2.22); each pair ofwheels (2.11, 2.12, 2.21, 2.22) is turned by a hydraulic motor(3.11,3.12,3.21,3.22).

[0020] Each hydraulic motor is equipped with suitable connections (4)for the pressure pump (not shown in the figure). There is no need for arigid connection between the control unit and the trolley assembly,since a connection for the passage of the fluid is sufficient.

[0021]FIG. 3 shows an interesting compact solution in which the trolleyassembly is connected, by means of an extensible bar (5.1), to thecontrol unit (6).

[0022] The extensible bar (5.1) is hinged in point (6.1) to reduce thebulk of the trolley when it is put away.

[0023] These are sufficient schematic indications to allow an expert toimplement the invention; consequently, in the tangible application itmay be subject to variations without prejudice to the substance of theinnovative concept.

[0024] With reference to the above description and to the encloseddrawings, the following claims are therefore put forth.

1. Motor-driven transport trolley comprising a frame with two sets ofwheels, right and left, characterized in that it is equipped with two ormore hydraulic motors which move the two sets of wheels separately toobtain differentiated drive, and having a rotating plate placed on top.2. Transport trolley according to claim 1 , characterized in that themotors are hydraulic and are fed by a pressure pump, and wherein themotion is differently distributed to the various hydraulic motors bymeans of valves connected to a control unit which controls the operationof the hydraulic motors, the pressure pump and the valves.
 3. Transporttrolley according to claims 1, 2, characterized in that the control unitis controlled by a push-button panel connected to it by means of anelectric cable, infrared rays or radio waves, etc.